It is not currently possible to work with specific units in FreeCAD. At the moment it works with "generic" units (one unit is one unit, you decide what one unit is). There is already a framework in place to build a unit system in FreeCAD, but it is a complicated matter (specially US imperial units) and no developper had time to do it already. But it is in the plans.
About meetings, actually there has never been any FreeCAD meeting yet!
i would like know how change the unit for drawing ?
if is possible or no ?
i would like know if there are a freecad meeting in france ?